The unpackaged size of the downloaded software will vary depending on the packages you select and - if you choose a binary distribution - the architecture selected. The full source code distribution is roughly 590 Mb. Complete binary distribution sizes are approximately: Linux PC (660 Mb), Linux PC 64-bit (770 Mb), Linux Mac (580 Mb), Mac PPC Darwin (750 Mb), Mac Intel Darwin (800 Mb), Solaris (1 Gb), and Cygwin (300 Mb). Individual binary packages range in size from only a few Mb to around 200 Mb for the Xspec distributions, as the Xspec distributions include a number of large data files required to run Xspec. The APEC NEI data files (which are only needed by users running APEC NEI models) are packaged separately.

The BUILD_DIR/configure script accepts the options
--with-copt, --with-cxxopt, and --with-fopt
with which you can set the optimization for each compiler (C/C++/Fortran).
For example, to reduce C and C++ optimization from -O2 to -O, and turn
off Fortran optimization, you would run
configure --with-copt=-O --with-cxxopt=-O --with-fopt=none.

Specify all parameters that you don't want the user prompted for on
the command line using the parameter="value" syntax. Specify *all*
hidden parameters (you're only going to type it once, so don't whine).
For example:

In the past, this FAQ mentioned a way to run FTOOLS using
mode=h. While not particularly dangerous when used *interactively*
by an experienced user, we no longer recommend this method; it's
too easy for inexperienced users to shoot themselves in the foot.

DO NOT use mode=h, in scripts!
DO NOT use 'pset' to set up an FTOOL to run!
(This is the number one generator of "bugs which aren't really bugs"
on ftoolshelp.)
DO always specify *all* parameters on the command line in scripts.

Most of the FTOOLS now have a clobber parameter. Just set
clobber=yes (on the command line or with pset) and your output files
will be cheerfully overwritten. In a less hazardous solution, most of
the FTOOLS also will clobber an output file if you precede the file
name with an exclamation mark. If your favorite FTOOL doesn't obey
this convention, let us know, and we'll fix it for the next release.

From the command line "fhelp ftools" will list all of the FTOOLS and
Perl scripts with a short description of each. More and more specific
help can be requested; for example "fhelp xte" will list the FTOOLS in
the XTE subpackage, and "fhelp fdump" will yield the full help page
for the fdump FTOOL.

So do I. Luckily, the FTOOLS parameter interface (XPI) uses the GNU
readline library, so a full set of command line editing features is
available (the same as you'd get in bash, for example). A few of the
more useful keys:

Key

Action

TAB

Filename completion. (Two tabs will show
you a list of possible completions if there's
an ambiguity).

up arrow (or ^p)

Recall previously entered line.

down arrow (or ^n)

"Undoes" up arrow.

right arrow (or ^f)

Move cursor right on current line.

left arrow (or ^b)

Move cursor left on current line.

RETURN

Enters the parameter you've just typed. (Your
cursor does not need to be at the end of the
line.)

Due to a feature added to one of the core library routines with
FTOOLS v4.1, if a string containing a forward slash ('/') is
given as the keyword value (eg, in a unix path), only
the characters preceding the slash will be interpreted as the
keyword's value while those following it will be the comment.
When entered interactively in response to fparkey's prompt,
surrounding the string in single quotes prevents this parsing. When
entered on the command line, however, 2 sets of quotes are
required (one single and one double) because unix strips off one
set before passing the string to the program. It thus looks like
either this: